Visual crucible cover for sapphire growth furnace

Abstract

The invention relates to a visual crucible cover for a sapphire growth furnace. The visual crucible cover comprises multiple layers of ring plates, wherein the ring plates are penetrated and fixed into a whole by virtue of a tungsten screw unit; U-shaped isolation pads are arranged between the ring plates; the ring plates are arranged from top to bottom, the inner diameters of the ring plates are gradually increased, and the outer diameters of the ring plates are gradually increased; observation holes are formed in the ring plates; and all the ring plates penetrate through the observation holes. According to the crucible cover disclosed by the invention, a mode of combining the tungsten ring plates on the lower layer and the molybdenum ring plates on the upper layer is adopted, and the U-shaped isolation pads are arranged between the ring plates, so that the cost is saved, a certain structural strength of the whole crucible cover can be guaranteed, the service life of the whole crucible cover is prolonged, and the phenomena that the temperature gradient at the upper end of the crucible opening changes due to severe deformation and the purity of the raw materials is influenced due to drop of volatile matters and impurities are effectively avoided.

Description

technical field [0001] The invention relates to the field of crystal growth technology and equipment, in particular to a visible crucible cover for a sapphire growth furnace. Background technique [0002] The sapphire crystal growth temperature is about 2050°C. When growing sapphire single crystals, especially large-sized sapphire single crystals, in order to maintain the temperature in the furnace and control a reasonable temperature gradient, the requirements for the insulation system are relatively strict. The heat preservation structure includes the crucible cover, the upper and lower heat shields, the heat preservation cylinder, the heat preservation filler and so on. Due to the high growth temperature of sapphire single crystal, the thermal insulation material is required to have high mechanical and thermal load capacity. Strengthen the heat preservation in the low temperature area, control the temperature gradient and the superheating temperature in the high temperat...

AI Technical Summary

Problems solved by technology

[0005] The seed crystal socket and observation window of the existing crucible cover are all set at the center of the crucible cover. When the crystal size is greater than 80Kg, the opening size must be increased to observe the growth of the crystal with shoulders and diameter control. When the crucible cover When the opening in the middle is large, it will not only affect the thermal insulation performance of the crucible lid and the temperature gradient of crystal growth, but also impurities will fall into the growth melt more easily from the opening.

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